US5992231A - Apparatus for measuring the quality of a fluid in a vessel - Google Patents
Apparatus for measuring the quality of a fluid in a vessel Download PDFInfo
- Publication number
- US5992231A US5992231A US09/031,690 US3169098A US5992231A US 5992231 A US5992231 A US 5992231A US 3169098 A US3169098 A US 3169098A US 5992231 A US5992231 A US 5992231A
- Authority
- US
- United States
- Prior art keywords
- electrode
- measuring
- circuit
- compensation
- space
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
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Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/24—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of resistance of resistors due to contact with conductor fluid
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
- G01F23/26—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields
- G01F23/263—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields by measuring variations in capacitance of capacitors
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
- G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
- G01N27/06—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of a liquid
- G01N27/07—Construction of measuring vessels; Electrodes therefor
Definitions
- the present invention relates to an apparatus for determining the condition of a fluid in a space, comprising:
- a measuring circuit for measuring the impedance between the measuring electrode and the second electrode and calculating the condition of the fluid from the impedance.
- Fluid is herein understood to mean not only a gas or a liquid but also ocher substances behaving as a fluid, such as granulates and substances in powder form.
- This known apparatus measures not only the capacity between the measuring electrode and the second electrode but also the ohmic resistance connected in parallel thereto, or the conductivity of the product between the measuring electrode and the second electrode. It will be apparent that the measurement result is influenced hereby.
- This known apparatus moreover has the drawback that when the dielectric constant of the substance present in the space is not known precisely, the measurement signal is a function of the dielectric constant of the substance and of the degree of filling.
- the object of the present invention is therefore to provide such an apparatus which offers more possibilities for measuring electrical properties of the substance present in the space.
- a measuring electrode extends at least partially uncovered in the space.
- the apparatus known from WO 96/24823 is always provided with an electrode provided with an external protective layer. It is thus not possible herewith to measure for instance the ohmic resistance of the substance present in the vessel, since the ohmic resistance of the protective material is usually so high that the resistance of the material connected thereto in series is hardly measurable and certainly cannot result in measurement signals of the required accuracy.
- the apparatus according to the invention can be applied in a space which is bounded by a vessel, wherein the second electrode is formed by at least one conductive part of the vessel wall.
- the apparatus according to the invention can also be applied in a space wherein the second electrode is formed by earth or by an auxiliary electrode extending around the measuring electrode.
- the apparatus is therefore provided with a measuring circuit which is adapted to measure the ohmic impedance between the measuring electrode and the auxiliary electrode.
- a measuring circuit which is adapted to measure the ohmic impedance between the measuring electrode and the auxiliary electrode.
- the present electrode also enables determining of the capacity between electrode and second electrode. With such an apparatus it is thus possible on the one hand to choose the most suitable measuring method, while the option is provided on the other to use both measuring methods alternately.
- the electrode is preferably received in a support, wherein the measuring electrode is separated from the earthed parts of the vessel wall by a compensation electrode which is connected to the compensation circuit.
- the compensation electrode has a mechanically supporting function and the measuring electrode is connected to the compensation electrode by means of an insulating connecting element, wherein an electrical connection between the measuring electrode and the measuring circuit extends through the compensation electrode embodied in hollow form.
- the level of the material in the vessel lies below or above a determined threshold value. This is for instance important in particular process controls or it may be important in safety measures.
- FIG. 1 shows a partly broken away perspective view of a vessel in which is arranged an apparatus according to the present invention
- FIG. 2 shows a view partially in cross-section of an electrode for use in the apparatus according to the present invention
- FIG. 3 shows a view partially in cross-section of a variant of an electrode with an auxiliary electrode according to the invention.
- FIG. 4 shows a diagram of the electrical circuit according to the present invention.
- FIG. 1 shows a vessel 1 which is manufactured from conductive material and on which is placed a cover 2.
- an electrode 3 which is formed by an actual measuring electrode 4 and a guard electrode 5.
- the compensation electrode 5 takes a hollow form and an electrical connection 6 extends through compensation electrode 5 to a junction box 7 arranged on top of the cover.
- the compensation electrode embodied in hollow form is connected to the junction box with a connection 8.
- a further guard electrode 9 which is connected to the rest of housing 1, in particular to cover 2.
- the whole assembly of vessel 1, cover 2 and electrode 9 is earthed.
- a possible cathodic protection device is herein omitted. Even if such a cathodic protection device is present, the entire above mentioned assembly is deemed as earthed in respect of the measuring system.
- the actual measuring electrode 4 is not provided with a protective layer as is the case in the prior art measuring apparatus. This has the consequence that, as in the prior art, the electrode can be used to measure the capacity between vessel wall and electrode, but also to measure the ohmic resistance between vessel wall and electrode.
- the advantages hereof have been pointed out in the description introduction.
- the protective layer of insulating material usually had the function of protecting the electrode against aggressive substances accommodated in the vessel and to prevent so-called "adhesion" of granulate-type substances to the electrode as the vessel empties.
- FIG. 2 shows the electrode 3 in its entirety, wherein the whole assembly of measuring electrode 4, compensation electrode 5 and guard electrode 9 is connected over a lead-through 10 to the box 7.
- lead-through 10 takes a hollow form, since connections 6 and 8 must extend therethrough to the box 7.
- Lead-through 10 is generally embodied in conductive material and is connected to guard electrode 9 by means of for instance a weld connection 11.
- Compensation electrode 5 must of course be deployed in electrically insulating manner relative to the guard electrode 9.
- a coupling piece 12 which in the present embodiment is embodied in ceramic material. Such coupling pieces of ceramic material are provided with a rail 13 to prevent bridge formation of powder or granular material or of liquids at a potential transition between guard electrode 9 and compensation electrode 5.
- the measuring electrode 4 extends over only a short length. This is related to a specific application of the present invention, wherein all that is determined is whether a quality of the substance lies below or above a determined point; an example hereof is whether or not the degree of filling of the vessel with a particular substance has exceeded a determined threshold value.
- Such an apparatus can also be used to measure the dielectric constant, respectively the resistance of a determined material. Such a measurement may be of significance for instance in process controls.
- the present invention is however in no way limited thereto; it is very well possible for instance, though not necessary, to generate a signal with a longer measuring electrode, a property of which signal represents a quality of the substance present in the vessel.
- the invention limited to the shown electrode configuration; it is possible to make use of earth as second electrode; the measuring circuit then measures against earth.
- auxiliary electrode as second electrode. Such an embodiment is shown in FIG. 3.
- An auxiliary electrode 25 in the form of a hollow cylinder is herein arranged round the electrode 3.
- This hollow cylinder 25 is manufactured from conductive material and is connected to earth in the drawn embodiment with a flange 26.
- Holes 27 are arranged in hollow cylinder 25. These holes serve to cause the level of the material in the space between electrode 3 and hollow cylinder 25 to be as far as possible the same as the level of the fluid in the space outside the hollow cylinder. This is in any case essential for performing a measurement as representative as possible of the actual level. The presence of the material in question in the space between the electrode and the hollow cylinder is of course also important for measuring the properties of the fluid.
- the most important function of the hollow cylinder is to make smaller the distance between the measuring electrode and the second electrode. This provides the option of performing a reliable measurement within the measuring range of the apparatus even in the case of high values of the specific electrical resistance or of low values of the dielectric constant of the fluid.
- a secondary function lies in the mechanical protection of the actual measuring electrode, particularly but not exclusively in flowing fluids.
- the above stated embodiments all have a measuring electrode body which is rigidly mounted on the vessel or the cover of the vessel. It is also possible however to suspend the electrode body from a cable. Only the actual measuring electrode need herein be suspended; in respect of the large distance between vessel wall and measuring electrode, the compensation electrode can be omitted.
- FIG. 4 An embodiment of the circuit required for performing the measurements is shown schematically in FIG. 4. Use is made herein of a circuit which is accommodated for instance in the junction box 7; it is very well possible however for the measuring circuit to be situated at a different point.
- the circuit essentially comprises a safety circuit 15, a power supply and conversion circuit 16 and a microprocessor 17. It is pointed out herein that safety circuit 15 is connected to the supply connections 19 by means of two melting electrodes 18.
- the melting fuses 18 are in any case necessary because this is a compulsory directive of safety regulations in a large number of countries. In the case of failure of such a melting fuse, which is usually arranged in the circuit at very inaccessible locations, being for instance moulded therein,. the whole circuit must be removed. In order to prevent these problems an electronic safety circuit 15 is applied which already responds at a lower level of current respectively voltage, hereby protecting the circuit and avoiding melting through of fuses 18.
- the power supply circuit 16 serves to convert the supply signal to a value with which microprocessor 17 and the other circuits can be supplied.
- the apparatus subsequently comprises a measuring circuit 20 for measuring the capacity and for measuring the ohmic resistance.
- Measuring circuit 20 for measuring the capacity has in essence already been described.
- a measuring circuit for measuring the capacity is already discussed in the above mentioned international patent publication.
- For measuring the ohmic resistance use is made of the same circuit 20, which can also be provided with for instance a classic measuring bridge. It is herein possible to apply numerous measuring principles which will all be clear to skilled persons. It is noted herein that the measuring circuit is thus suitable for alternately performing both measuring functions, i.e. measuring of the capacity between the electrodes and measuring of the resistance between the electrodes.
- the measuring apparatus further comprises an auxiliary circuit 21 which converts the signal received from measuring circuit 20 into a signal representing the ohmic resistance.
- Both measuring circuits 20 and 21 are controlled by the selector circuit 22 which can cause measuring circuit 20 to measure the ohmic resistance or the capacity.
- measuring electrode 4 compensation electrode 5 and earth electrode 9 are connected to measuring circuit 20. Use is made herein of an earth connection 23.
- the relevant part of the circuit can then be omitted. In other situations it is attractive to measure both elements; to this end the microprocessor 17 can be programmed such that measuring circuit 20 alternately measures ohmic resistance and capacity. The measurement signals resulting herefrom can then be processed in microprocessor 17 and converted into associated information signals which can be transmitted via supply lines 19 to the central processing circuit not shown in the drawing.
- microprocessor 17 and measuring circuits 20, 21 and 22 there is of course a galvanic separation present in order to obtain a necessary galvanic separation between the earthed vessel and the other measurement signals.
- This galvanic separation can otherwise also be arranged at other locations in the circuit.
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- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- General Health & Medical Sciences (AREA)
- Immunology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- Electrochemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Pathology (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
Abstract
Description
Claims (20)
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL1005421A NL1005421C2 (en) | 1997-03-03 | 1997-03-03 | Improved device for measuring the quality of a fluid in a vessel. |
US09/031,690 US5992231A (en) | 1997-03-03 | 1998-02-27 | Apparatus for measuring the quality of a fluid in a vessel |
CA002230867A CA2230867C (en) | 1997-03-03 | 1998-03-02 | Improved apparatus for measuring the quality of a fluid in a vessel |
DE19808940A DE19808940A1 (en) | 1997-03-03 | 1998-03-03 | System for determining quality of fluid in chamber |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL1005421A NL1005421C2 (en) | 1997-03-03 | 1997-03-03 | Improved device for measuring the quality of a fluid in a vessel. |
US09/031,690 US5992231A (en) | 1997-03-03 | 1998-02-27 | Apparatus for measuring the quality of a fluid in a vessel |
Publications (1)
Publication Number | Publication Date |
---|---|
US5992231A true US5992231A (en) | 1999-11-30 |
Family
ID=26642548
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US09/031,690 Expired - Lifetime US5992231A (en) | 1997-03-03 | 1998-02-27 | Apparatus for measuring the quality of a fluid in a vessel |
Country Status (4)
Country | Link |
---|---|
US (1) | US5992231A (en) |
CA (1) | CA2230867C (en) |
DE (1) | DE19808940A1 (en) |
NL (1) | NL1005421C2 (en) |
Cited By (16)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020175822A1 (en) * | 2001-05-24 | 2002-11-28 | Potter Electric Signal Company | Low-water cut-off system |
US20030189433A1 (en) * | 2002-04-08 | 2003-10-09 | Nanmat Technology Co., Ltd. | Method for detecting quantity variation of high purity liquid chemicals and devices to carry out the method |
US6640644B1 (en) | 2002-05-17 | 2003-11-04 | Delphi Technologies, Inc. | Apparatus and method for detecting tilt and vibration of a body |
US20040123659A1 (en) * | 2001-05-24 | 2004-07-01 | Jeffrey Merwin | Low-water cut-off system |
US20070219731A1 (en) * | 2006-03-15 | 2007-09-20 | Merwin Jeffrey C | Fluid detector recognizing foam and surge conditions |
US20070234796A1 (en) * | 2006-02-14 | 2007-10-11 | Tshishiku Eugene M | Liquid level detector |
US20080307882A1 (en) * | 2005-06-03 | 2008-12-18 | Holger Schroter | Capacitive Level Probe |
US20110240475A1 (en) * | 2008-12-10 | 2011-10-06 | Stefan Hother | Conductivity meter and liquid treatment device |
US20120086429A1 (en) * | 2010-10-08 | 2012-04-12 | Poet Research, Inc. | Method and apparatus for measuring moisture content |
US20120261004A1 (en) * | 2009-12-22 | 2012-10-18 | Endress + Hauser Wetzer Gmbh + Co. Kg | Installation Assembly |
US20130269421A1 (en) * | 2012-03-22 | 2013-10-17 | Airbus Operations Limited | Sensor device and method for communicating with sensor devices |
US20160116322A1 (en) * | 2013-05-08 | 2016-04-28 | Endress + Hauser Gmbh + Co. Kg | Method for monitoring at least one media-specific property of a medium |
US10281312B2 (en) | 2013-03-01 | 2019-05-07 | Endress+Hauser Se+Co.Kg | Method and apparatus for monitoring a predefined filling level of a medium in a container |
US10416020B2 (en) * | 2014-06-05 | 2019-09-17 | Endress+Hauser Se+Co.Kg | Method and apparatus for monitoring fill level of a medium in a container |
EP3696539A1 (en) * | 2019-02-15 | 2020-08-19 | Evonik Operations GmbH | Device and method for measuring the electrical conductivity and/or the electrical potential of an aggressive viscous medium under hostile conditions |
US10906379B1 (en) | 2016-11-29 | 2021-02-02 | TSI Products, Inc. | Compact air conditioning apparatus, cord harness and method of use thereof |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6377052B1 (en) * | 1999-11-03 | 2002-04-23 | Eaton Corporation | Monitoring fluid condition through an aperture |
FR2919719B1 (en) * | 2007-08-01 | 2009-10-23 | Atlantic Ind Soc Par Actions S | "DEVICE FOR DETERMINING A QUANTITY OF HOT WATER REMAINING" |
DE102020120921A1 (en) | 2020-08-07 | 2022-02-10 | AST (Advanced Sensor Technologies) International GmbH | Sensor arrangement for determining a quality of a liquid and method |
Citations (8)
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GB1279204A (en) * | 1970-03-19 | 1972-06-28 | L T H Electronics Ltd | Shot blasting of liquid conductivity cell electrodes |
US4551785A (en) * | 1983-08-04 | 1985-11-05 | Endress U. Hauser Gmbh U. Co. | Capacitive sensor |
US4757252A (en) * | 1985-10-25 | 1988-07-12 | Drexelbrook Controls, Inc. | Probe system for measuring the condition of materials |
US4806847A (en) * | 1986-12-09 | 1989-02-21 | Caterpillar Inc. | Dielectric liquid level sensor and method |
WO1992022808A1 (en) * | 1991-06-18 | 1992-12-23 | Minntech Corporation | Sensor for peracetic acid-hydrogen peroxide solution |
US5391839A (en) * | 1991-06-07 | 1995-02-21 | Endress + Hauser Gmbh + Co. | Device for the electrically insulated attachment of a metallic probe electrode in the opening of a housing |
US5546005A (en) * | 1995-01-09 | 1996-08-13 | Flowline Inc. | Guarded capacitance probe and related measurement circuit |
WO1996024823A2 (en) * | 1995-02-06 | 1996-08-15 | Meridian Instruments B.V. | Apparatus for capacitive measurements |
-
1997
- 1997-03-03 NL NL1005421A patent/NL1005421C2/en not_active IP Right Cessation
-
1998
- 1998-02-27 US US09/031,690 patent/US5992231A/en not_active Expired - Lifetime
- 1998-03-02 CA CA002230867A patent/CA2230867C/en not_active Expired - Fee Related
- 1998-03-03 DE DE19808940A patent/DE19808940A1/en not_active Withdrawn
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB1279204A (en) * | 1970-03-19 | 1972-06-28 | L T H Electronics Ltd | Shot blasting of liquid conductivity cell electrodes |
US4551785A (en) * | 1983-08-04 | 1985-11-05 | Endress U. Hauser Gmbh U. Co. | Capacitive sensor |
US4757252A (en) * | 1985-10-25 | 1988-07-12 | Drexelbrook Controls, Inc. | Probe system for measuring the condition of materials |
US4806847A (en) * | 1986-12-09 | 1989-02-21 | Caterpillar Inc. | Dielectric liquid level sensor and method |
US5391839A (en) * | 1991-06-07 | 1995-02-21 | Endress + Hauser Gmbh + Co. | Device for the electrically insulated attachment of a metallic probe electrode in the opening of a housing |
WO1992022808A1 (en) * | 1991-06-18 | 1992-12-23 | Minntech Corporation | Sensor for peracetic acid-hydrogen peroxide solution |
US5546005A (en) * | 1995-01-09 | 1996-08-13 | Flowline Inc. | Guarded capacitance probe and related measurement circuit |
WO1996024823A2 (en) * | 1995-02-06 | 1996-08-15 | Meridian Instruments B.V. | Apparatus for capacitive measurements |
Cited By (23)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US20020175822A1 (en) * | 2001-05-24 | 2002-11-28 | Potter Electric Signal Company | Low-water cut-off system |
US20040123659A1 (en) * | 2001-05-24 | 2004-07-01 | Jeffrey Merwin | Low-water cut-off system |
US6904800B2 (en) | 2001-05-24 | 2005-06-14 | Potter Electric Signal Company | Low-water cut-off system |
US7243540B2 (en) | 2001-05-24 | 2007-07-17 | Potter Electric Signal Company | Low-water cut-off system |
US20030189433A1 (en) * | 2002-04-08 | 2003-10-09 | Nanmat Technology Co., Ltd. | Method for detecting quantity variation of high purity liquid chemicals and devices to carry out the method |
US6734686B2 (en) * | 2002-04-08 | 2004-05-11 | Nanmat Technology Co. Ltd. | Method for detecting quantity variation of high purity liquid chemicals and devices to carry out the method |
US6640644B1 (en) | 2002-05-17 | 2003-11-04 | Delphi Technologies, Inc. | Apparatus and method for detecting tilt and vibration of a body |
US20080307882A1 (en) * | 2005-06-03 | 2008-12-18 | Holger Schroter | Capacitive Level Probe |
US20070234796A1 (en) * | 2006-02-14 | 2007-10-11 | Tshishiku Eugene M | Liquid level detector |
US7992437B2 (en) * | 2006-02-14 | 2011-08-09 | Savannah River Nuclear Solutions, Llc | Liquid level detector |
US7317993B2 (en) | 2006-03-15 | 2008-01-08 | Potter Electric Signal Company | Fluid detector recognizing foam and surge conditions |
US20070219731A1 (en) * | 2006-03-15 | 2007-09-20 | Merwin Jeffrey C | Fluid detector recognizing foam and surge conditions |
US20110240475A1 (en) * | 2008-12-10 | 2011-10-06 | Stefan Hother | Conductivity meter and liquid treatment device |
US20120261004A1 (en) * | 2009-12-22 | 2012-10-18 | Endress + Hauser Wetzer Gmbh + Co. Kg | Installation Assembly |
US20120086429A1 (en) * | 2010-10-08 | 2012-04-12 | Poet Research, Inc. | Method and apparatus for measuring moisture content |
US9523652B2 (en) * | 2010-10-08 | 2016-12-20 | Poet Research, Inc. | Method and apparatus for measuring moisture content |
US20130269421A1 (en) * | 2012-03-22 | 2013-10-17 | Airbus Operations Limited | Sensor device and method for communicating with sensor devices |
US10281312B2 (en) | 2013-03-01 | 2019-05-07 | Endress+Hauser Se+Co.Kg | Method and apparatus for monitoring a predefined filling level of a medium in a container |
US20160116322A1 (en) * | 2013-05-08 | 2016-04-28 | Endress + Hauser Gmbh + Co. Kg | Method for monitoring at least one media-specific property of a medium |
US10422680B2 (en) * | 2013-05-08 | 2019-09-24 | Endress+Hauser Se+Co.Kg | Method for monitoring at least one media-specific property of a medium |
US10416020B2 (en) * | 2014-06-05 | 2019-09-17 | Endress+Hauser Se+Co.Kg | Method and apparatus for monitoring fill level of a medium in a container |
US10906379B1 (en) | 2016-11-29 | 2021-02-02 | TSI Products, Inc. | Compact air conditioning apparatus, cord harness and method of use thereof |
EP3696539A1 (en) * | 2019-02-15 | 2020-08-19 | Evonik Operations GmbH | Device and method for measuring the electrical conductivity and/or the electrical potential of an aggressive viscous medium under hostile conditions |
Also Published As
Publication number | Publication date |
---|---|
DE19808940A1 (en) | 1998-10-08 |
CA2230867A1 (en) | 1998-09-03 |
NL1005421C2 (en) | 1998-09-18 |
CA2230867C (en) | 2004-10-26 |
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